1. 1 Usage of the Cluster Data in ILWS Studies Harri Laakso, Philippe Escoubet, Matt Taylor, and Arnaud Masson European Space Agency (ESA) Science and Robotic Exploration Directorate Noordwijk, The Netherlands ILWS 2009, Ubatuba, Brazil, 4-9 October 2009 Contents:  Introduction to Cluster observations  Introduction to Cluster data archive* * An ESA contribution to the ILWS

2. 2 Introduction to the Cluster Mission  Cluster is a four-satellite constellation mission where the satellite separations are controlled and varied between 100 – 10 000 km  The satellites are on a polar-orbit with the orbital period, perigee distance and apogee distance of 55 hours, <4 Re and 19 Re, respectively  The spacecraft were launched in summer 2000 and the science operations started on 1 February 2001. The mission has been extended until December 2012  The key dayside investigations: solar wind, bow shock, magnetopause and cusp  The key nightside investigations: auroral zone, plasma sheet, radiation belts and plasmasphere  Two Cluster workshops are organized annually: there are usually 100+ participants and are open to all scientists, for details, see http://caa.estec.esa.int/wksp/cluster_workshop_home.xml

3. 3 Cluster Instruments Particle experiments:  PEACE Thermal electrons with energies <30 keV  CIS Thermal ions (including composition) below 40 keV  RAPID High energy electrons and ions below 450 keV (Ei>10 keV, Ee>20 keV)  EDI Plasma drift velocity and DC electric fields, with electron beam injection  ASPOC Spacecraft potential control, with ion current emission Fields & waves experiments:  FGM DC magnetic fields at 22 Hz (66 Hz in burst mode)  EFW DC electric fields at 25 Hz (450 Hz)  STAFF Magnetic and electric fluctuations <4 kHz (use search coil & EFW sensors)  WHISPER Electron density (0.1-80 cc) and plasma waves (2-80 kHz)  WBD Electric field waveforms <500 kHz  DWP Wave processor and wave-particle correlator

4. 4 Polar cusp Solar wind Auroral zone Magnetopause Cluster Orbit in March-April

5. 5 Cluster Dayside Observations Auroral region Polar cap Cusp Dayside magnetosphere Magnetosheath Solar wind

6. 6 Cluster Orbit in September-October

7. 7 Cluster Nightside Observations Radiation belts/plasmasphere/ cusp Lobe Plasma sheet

8. 8 Solar wind Auroral zone: Acceleration region 2001 2008-2009 Magnetopause: subsolar point Cluster Orbit Evolution 2008 -

9. 9 Solar wind Near Earth tail: Current disruption 2001 2008-2009 Low altitude cusp Cluster Orbit Evolution 2008 -

10. 10  The Cluster Active Archive CAA (http://caa.estec.esa.int/) aims to ensure thathttp://caa.estec.esa.int/  The CAA will contain all Cluster high-resolution data as well as all allied (supporting) data products necessary to the full interpretation of the full- resolution datasets  the entire high- and low-resolution datasets are fully calibrated (to the level achievable within the limited resources available)  the data should be suitable for science use and publication by the world- wide scientific community  all data are provided in a standard format (CEF - Cluster Exchange Format) and with a complete set of metadata in machine readable form  the CAA will provide user friendly services for searching and accessing these data What is CAA?

11. 11 CAA Organigram-2009 Cluster Project Scientist (M Taylor) Deputy (A Masson) Project Manager (H Laakso) Technical Manager (C Perry) Working Groups (Chairs: C Harvey, A Allen) System Engineer (R Turner) ESOCJSOC PI: K Torkar E Georgescu PI: R Torbert E Kronberg PI: P Daly A Barthe PI: I Dandouras N Doss PI: A Fazakerley S Walker PI: H Alleyne C Burlaud PI: N Cornilleau-Wehrlin PI: J Pickett P French PI: E Lucek C Cully PI: M Andre G Facsko PI: J-G Trotignon Note: names in red color are contractors supported by the CAA project Archive Developers (S McCaffrey, D Herment, J. Kissi) CISASPOCEDIRAPIDDWPEFWWBDFGMSTAFFWHISPERPEACE

12. 12  The coverage and range of products are being continually improved, currently with over 200 datasets available from each spacecraft, including  high-resolution DC and AC B- & E-fields  full 3D electron & ion distributions for 0 eV - 400 keV  various ancillary & browse products  Most/many of the teams have provided the data files for years 2001- 2007  a number of complicated products, mainly due to calibration difficulties, are still partly missing  currently the teams are producing and delivering files for year 2008 Status of the CAA Data Inventory

13. 13 CAA Access Point  The CAA operational since Feb 2006  Registration is necessary in order to have an access to the data and graphical products http://caa.estec.esa.int/

14. 14 Data Downloading  Two access routes to the data:  xml forms interface on the CAA web site  Command-line interface to automated download requests  Data selection can be based on spacecraft, experiment, measurement type, instrument type and/or time range

15. 15 User Profiles  Request can be stored as user profile to speed up subsequent requests:  provide an easy way to set- up and request standard selections from the large number of available CAA datasets.  can be used for machine accessible interface

16. 16 Command-line Request  Simple way of requesting data from the CAA database  Example: requesting a month of full-resolution FGM data from Cluster 1 in February 2001 in daily files in cdf format, one types wget "http://caa.estec.esa.int/caa_query/? uname=username&pwd=password& dataset_id=C1_CP_FGM_FULL& time_range=2001-02-01T00:00:00Z/2001-02-28T24:00:00Z& file_interval=1day& file_format=cdf"  one can also download files ingested into the system after a given day: ingestedsince=2008-01-01T00:00:00Z &  Details/definitions of using the tool are described in a user guide (available under Documentation)

17. 17 CAA User Activity  CAA has ~920 registered users  Every month ~150 different users log in the CAA  Every month CAA gets ~20 new users  The total data volume downloaded is ~0.5 TB per month

18. 18 These plots are produced by CAA using the calibrated CAA data products User can select and arrange individual panels Selected set can be saved as a user profile Plots on screen are in png whereas the downloaded plots are in ps CAA Graphics

19. 19  Pre-generated CAA plots based on the CAA database  1-hr, 6-hr and 24-hr plots are available CAA Graphics

20. 20  provided by the instrument teams and the CSDS (CSDSweb) quick-look system  not well calibrated i.e. not suitable to science  Plots useful for event identifications  links to the database selection interface with the time pre-selected based on the current plot interval Quick-Look Plots, 1

21. 21 Quick-Look Plots, 2

22. 22 New GUI For Downloading

23. 23 New GUI For Downloading

24. 24  Activity: observations from different Cluster instruments are compared in detail both statistically and on event basis. This is essential to the the production of high-quality data products. Minutes and presentations of the past workshops can be found at http://caa.estec.esa.int/caa/cross-cal.xml  The following workshops have been organized: CAA Cross-Calibration Workshops Kick-off Cross-Cal Meeting ESTEC, Netherlands23 Sep 2005 1 st Cross-Cal Workshop ESTEC, Netherlands2-3 Feb 2006 2 nd Cross-Cal WorkshopESTEC, Netherlands16 May 2006 3 rd Cross-Cal WorkshopMSSL, London, UK26-27 Oc 2006 4 th Cross-Cal WorkshopLPCE, Orleans, France12-13 Feb 2007 5 th Cross-Cal WorkshopESTEC, Netherlands14 May 2007 6 th Cross-Cal WorkshopImperial College, London, UK24-25 Oct 2007 7 th Cross-Cal WorkshopTenerife, Spain9 Mar 2008 8 th Cross-Cal WorkshopKinsale, Ireland28-30 Oct 2008 9 th Cross-Cal WorkshopCambridge, UK25-27 Mar 2009 10 th Cross-Cal WorkshopParis, France2-4 Nov 2009

25. 25 Documentation

26. 26 CEF FORMAT  All the science-quality digital data products are provided to the CAA in a standard representation, the Cluster Exchange Format (CEF)  Full descriptions of the data format and meta-data standards used by the CAA can be accessed from the documents area of the CAA web site http://caa.estec.esa.int/caa/documentation.xml  The CEF  is an ASCII, comma separated, tabular format supporting multi-line records  has a fully self-describing header  offers straightforward long-term accessibility to the Cluster data  On download, products can optionally be converted to the widely used NASA Common Data Format (CDF)

27. 27 Software  MATLAB & IDL tools for reading and displaying data in CEF-format  QSAS for reading & displaying CEF data  Instrument team software for displaying their data  etc

28. 28  Cluster is a four-satellite constellation mission:  Cluster science: detailed investigations of physical processes in space plasmas around the Earth  Single satellite observations can be very valuable for global magnetospheric studies, e.g., in the spring-time the spacecraft stays in the solar wind ~24 hours every few days, or in the autumn-time similarly in the plasma sheet  The Cluster observations are available since 1 February 2001  All full- and spin-resolution Cluster data available to the world-wide science community through the Cluster Active Archive CAA (http://caa.estec.esa.int/)http://caa.estec.esa.int/  All data are aimed to be well calibrated (done with limited resources)  all data are provided in a standard format (CEF - Cluster Exchange Format) with a complete set of metadata in machine readable form  All data can also be downloaded in CDF format  Currently there are about 20-30 TB of data in compressed format  If there are any issues on the usability and quality of the data products, one can contact the CAA by sending an e-mail to caateam@rssd.esa.int, or filling in a feedback form at http://caa.estec.esa.int/caa/feedback_intro.xmlcaateam@rssd.esa.inthttp://caa.estec.esa.int/caa/feedback_intro.xml Summary